Inhaled corticosteroid adherence in paediatric patients: the PACMAN cohort study

Poor adherence with inhaled corticosteroids (ICSs) has been reported frequently and may be associated with uncontrolled asthma. A better understanding of factors influencing adherence may help to achieve higher adherence rates for a larger part of the population, which will eventually lead to better asthma control. The aim of this study was to investigate factors associated with adherence in paediatric ICS users.

We included 527 children using ICSs who participated in the Pharmacogenetics of Asthma Medication in Children: Medication with Anti-inflammatory Effects (PACMAN) cohort study. The outcome, a parent-reported adherence, was assessed by using the Medication Adherence Report Scale. Four categories of determinants were studied: child characteristics, family characteristics, medication use (parental beliefs towards medication; using Beliefs about Medicines Questionnaire) and environmental factors.

Good adherence was observed in 302 children (57%). Increased fractional exhaled nitric oxide values (indication for airway inflammation) were associated with a lower chance of good adherence (OR = 0.25, 95%CI = 0.15-0.41). Parental necessity beliefs about medication were associated with higher adherence (OR = 2.32, 95%CI = 1.59-3.39). Dutch origin was also associated with higher adherence rates (OR = 2.11, 95%CI = 1.09-4.07). Furthermore, younger age (< 6 years) was associated with better adherence (OR = 1.62, 95%CI = 1.02-2.59).

Increased airway inflammation was associated with lower ICS adherence, which underlines the need of good adherence to reach disease control. Our results suggest that by improving knowledge, especially in ethnic minorities, and by stimulating positive parental perception towards the nature of the disease, the characteristics of the prescribed drugs and the use of medications, better adherence and as a result better asthma control could be reached.